From 140f4a315b4b1bb5402a78b37756aa6c212ed390 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sun, 19 Dec 2010 03:02:34 +0000 Subject: first step to fixing PR8642: don't fold away empty basic blocks which have trapping constant exprs in them due to PHI nodes. Eliminating them can cause the constant expr to be evalutated on new paths if the input edges are critical. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122164 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/Transforms/CodeGenPrepare/basic.ll | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 test/Transforms/CodeGenPrepare/basic.ll (limited to 'test') diff --git a/test/Transforms/CodeGenPrepare/basic.ll b/test/Transforms/CodeGenPrepare/basic.ll new file mode 100644 index 0000000..04b4f34 --- /dev/null +++ b/test/Transforms/CodeGenPrepare/basic.ll @@ -0,0 +1,31 @@ +; RUN: opt -codegenprepare %s -S | FileCheck %s +; PR8642 + +%0 = type <{ %1, %1 }> +%1 = type { i8, i8, i8, i8 } + +@g_2 = global %0 <{ %1 { i8 1, i8 0, i8 0, i8 undef }, %1 { i8 2, i8 0, i8 0, i8 undef } }>, align 4 +@g_4 = global %1 { i8 3, i8 0, i8 0, i8 undef }, align 4 + +; CGP shouldn't fold away the empty cond.false.i block, because the constant +; expr that will get dropped into it could trap. +define i16 @test1(i8** %argv, i1 %c) nounwind ssp { +entry: + br i1 %c, label %cond.end.i, label %cond.false.i + +cond.false.i: ; preds = %entry + br label %foo.exit + +cond.end.i: ; preds = %entry + store i8* null, i8** %argv + br label %foo.exit + +foo.exit: ; preds = %cond.end.i, %cond.false.i + %call1 = phi i16 [ trunc (i32 srem (i32 1, i32 zext (i1 icmp eq (%1* bitcast (i8* getelementptr inbounds (%0* @g_2, i64 0, i32 1, i32 0) to %1*), %1* @g_4) to i32)) to i16), %cond.false.i ], [ 1, %cond.end.i ] + ret i16 %call1 + +; CHECK: @test1 +; CHECK: cond.false.i: +; CHECK-NEXT: br label %foo.exit +} + -- cgit v1.1